feat(repository): add GetRepositorySpecForComponent method (open-component-model#1887)

<!-- markdownlint-disable MD041 -->
#### What this PR does / why we need it
Introduces a new method to retrieve the repository specification for a
given component version, enhancing the transfer operations.

#### Which issue(s) this PR fixes
<!--
Usage: `Fixes #<issue number>`, or `Fixes (paste link of issue)`.
-->
Contributes to
open-component-model/ocm-project#905

#### Testing

##### How to test the changes

<!--
Required files to test the changes:

.ocmconfig
```yaml
type: generic.config.ocm.software/v1
configurations:
  - type: credentials.config.ocm.software
    repositories:
      - repository:
          type: DockerConfig/v1
          dockerConfigFile: "~/.docker/config.json"
```

Commands that test the change:

```bash
ocm get cv xxx

ocm transfer xxx
```
-->

##### Verification

- [ ] I have tested the changes locally by running `ocm`

Manual tests will be performed as part of the follow up TGD adjustment
PR:
open-component-model#1888

---------

Signed-off-by: Fabian Burth <fabian.burth@sap.com>

Author: fabianburth

bindings/go/repository/component/fallback/v1/repository.go

@@ -37,7 +37,8 @@ const Realm = "repository/component/fallback"
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 type FallbackRepository struct {
 	// GoRoutineLimit limits the number of active goroutines for concurrent
 	// operations.
@@ -78,7 +79,8 @@ type FallbackRepositoryOptions struct {
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func NewFallbackRepository(_ context.Context, repositoryProvider repository.ComponentVersionRepositoryProvider, credentialsResolver credentials.Resolver, res []*resolverruntime.Resolver, opts ...FallbackRepositoryOption) (*FallbackRepository, error) {
 	options := &FallbackRepositoryOptions{}
 	for _, opt := range opts {
@@ -111,7 +113,8 @@ func NewFallbackRepository(_ context.Context, repositoryProvider repository.Comp
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func (f *FallbackRepository) AddComponentVersion(ctx context.Context, descriptor *descriptor.Descriptor) error {
 	repos := f.RepositoriesForComponentIterator(ctx, descriptor.Component.Name)
 	for repo, err := range repos {
@@ -130,7 +133,8 @@ func (f *FallbackRepository) AddComponentVersion(ctx context.Context, descriptor
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func (f *FallbackRepository) GetComponentVersion(ctx context.Context, component, version string) (*descriptor.Descriptor, error) {
 	repos := f.RepositoriesForComponentIterator(ctx, component)
 	for repo, err := range repos {
@@ -157,7 +161,8 @@ func (f *FallbackRepository) GetComponentVersion(ctx context.Context, component,
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func (f *FallbackRepository) ListComponentVersions(ctx context.Context, component string) ([]string, error) {
 	repos := f.RepositoriesForComponentIterator(ctx, component)
 
@@ -207,7 +212,8 @@ func (f *FallbackRepository) ListComponentVersions(ctx context.Context, componen
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func (f *FallbackRepository) AddLocalResource(ctx context.Context, component, version string, res *descriptor.Resource, content blob.ReadOnlyBlob) (*descriptor.Resource, error) {
 	repos := f.RepositoriesForComponentIterator(ctx, component)
 	for repo, err := range repos {
@@ -226,7 +232,8 @@ func (f *FallbackRepository) AddLocalResource(ctx context.Context, component, ve
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func (f *FallbackRepository) GetLocalResource(ctx context.Context, component, version string, identity runtime.Identity) (blob.ReadOnlyBlob, *descriptor.Resource, error) {
 	repos := f.RepositoriesForComponentIterator(ctx, component)
 	for repo, err := range repos {
@@ -252,7 +259,8 @@ func (f *FallbackRepository) GetLocalResource(ctx context.Context, component, ve
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func (f *FallbackRepository) AddLocalSource(ctx context.Context, component, version string, source *descriptor.Source, content blob.ReadOnlyBlob) (*descriptor.Source, error) {
 	repos := f.RepositoriesForComponentIterator(ctx, component)
 	for repo, err := range repos {
@@ -271,7 +279,8 @@ func (f *FallbackRepository) AddLocalSource(ctx context.Context, component, vers
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func (f *FallbackRepository) GetLocalSource(ctx context.Context, component, version string, identity runtime.Identity) (blob.ReadOnlyBlob, *descriptor.Source, error) {
 	repos := f.RepositoriesForComponentIterator(ctx, component)
 	for repo, err := range repos {
@@ -299,7 +308,8 @@ func (f *FallbackRepository) GetLocalSource(ctx context.Context, component, vers
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func (f *FallbackRepository) RepositoriesForComponentIterator(ctx context.Context, component string) iter.Seq2[repository.ComponentVersionRepository, error] {
 	return func(yield func(repository.ComponentVersionRepository, error) bool) {
 		for _, resolver := range f.resolvers {
@@ -324,7 +334,8 @@ func (f *FallbackRepository) RepositoriesForComponentIterator(ctx context.Contex
 // Deprecated: FallbackRepository is an implementation for the deprecated config
 // type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
 // and only added for backwards compatibility.
-// New concepts will likely be introduced in the future (contributions welcome!).
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func (f *FallbackRepository) GetResolvers() []*resolverruntime.Resolver {
 	// Return a copy of the resolvers to ensure immutability
 	return deepCopyResolvers(f.resolvers)
@@ -358,10 +369,52 @@ func (f *FallbackRepository) getRepositoryForSpecification(ctx context.Context,
 	return repo, nil
 }
 
+// GetComponentVersionRepositoryForSpecification returns a repository for the given specification.
+//
+// Deprecated: FallbackRepository is an implementation for the deprecated config
+// type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
+// and only added for backwards compatibility.
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
 func (f *FallbackRepository) GetComponentVersionRepositoryForSpecification(ctx context.Context, specification runtime.Typed) (repository.ComponentVersionRepository, error) {
 	return f.getRepositoryFromCache(ctx, specification)
 }
 
+// GetRepositorySpecificationForComponent probes repositories in priority order and returns
+// the spec of the first repository that contains the component version.
+// Note: This does NOT cache results to maintain consistency with the existing
+// non-deterministic fallback behavior.
+//
+// Deprecated: FallbackRepository is an implementation for the deprecated config
+// type "ocm.config.ocm.software/v1". This concept of fallback resolvers is deprecated
+// and only added for backwards compatibility.
+// Use the path matcher resolver (ocm.software/open-component-model/bindings/go/repository/component/pathmatcher)
+// with "resolvers.ocm.software/v1alpha1" configuration instead.
+func (f *FallbackRepository) GetRepositorySpecificationForComponent(ctx context.Context, component, version string) (runtime.Typed, error) {
+	for _, resolver := range f.resolvers {
+		if resolver.Prefix != "" && resolver.Prefix != component &&
+			!strings.HasPrefix(component, strings.TrimSuffix(resolver.Prefix, "/")+"/") {
+			continue
+		}
+		repo, err := f.getRepositoryFromCache(ctx, resolver.Repository)
+		if err != nil {
+			return nil, fmt.Errorf("getting repository for resolver %v failed: %w", resolver, err)
+		}
+		_, err = repo.GetComponentVersion(ctx, component, version)
+		if errors.Is(err, repository.ErrNotFound) {
+			slog.DebugContext(ctx, "component version not found in repository during spec resolution",
+				"realm", Realm, "repository", resolver.Repository, "component", component, "version", version)
+			continue
+		}
+		if err != nil {
+			return nil, fmt.Errorf("probing component version %s/%s in repository %v failed: %w",
+				component, version, resolver.Repository, err)
+		}
+		return resolver.Repository, nil
+	}
+	return nil, fmt.Errorf("component version %s/%s not found in any repository", component, version)
+}
+
 func (f *FallbackRepository) getRepositoryFromCache(ctx context.Context, specification runtime.Typed) (repository.ComponentVersionRepository, error) {
 	specdata, err := json.Marshal(specification)
 	if err != nil {

bindings/go/repository/component/fallback/v1/repository_test.go

@@ -440,8 +440,23 @@ func (m MockRepository) AddComponentVersion(ctx context.Context, descriptor *des
 }
 
 func (m MockRepository) GetComponentVersion(ctx context.Context, component, version string) (*descriptor.Descriptor, error) {
-	//TODO implement me
-	panic("implement me")
+	if versions, ok := m.Components[component]; ok {
+		for _, v := range versions {
+			if v == version {
+				return &descriptor.Descriptor{
+					Component: descriptor.Component{
+						ComponentMeta: descriptor.ComponentMeta{
+							ObjectMeta: descriptor.ObjectMeta{
+								Name:    component,
+								Version: version,
+							},
+						},
+					},
+				}, nil
+			}
+		}
+	}
+	return nil, repository.ErrNotFound
 }
 
 func (m MockRepository) ListComponentVersions(ctx context.Context, component string) ([]string, error) {
@@ -468,3 +483,142 @@ func (m MockRepository) GetLocalSource(ctx context.Context, component, version s
 	//TODO implement me
 	panic("implement me")
 }
+
+func Test_GetRepositorySpecForComponent(t *testing.T) {
+	ctx := context.Background()
+
+	cases := []struct {
+		name         string
+		component    string
+		version      string
+		resolvers    []*resolverruntime.Resolver
+		expectedRepo string
+		assertErr    assert.ErrorAssertionFunc
+	}{
+		{
+			name:      "component found in first repository",
+			component: "ocm.software/test",
+			version:   "v1.0.0",
+			resolvers: []*resolverruntime.Resolver{
+				{
+					Repository: NewRepositorySpec("repo-a", map[string][]string{
+						"ocm.software/test": {"v1.0.0"},
+					}),
+					Prefix:   "",
+					Priority: 2,
+				},
+				{
+					Repository: NewRepositorySpec("repo-b", map[string][]string{
+						"ocm.software/other": {"v1.0.0"},
+					}),
+					Prefix:   "",
+					Priority: 1,
+				},
+			},
+			expectedRepo: "repo-a",
+			assertErr:    assert.NoError,
+		},
+		{
+			name:      "component found in second repository (not first)",
+			component: "ocm.software/other",
+			version:   "v1.0.0",
+			resolvers: []*resolverruntime.Resolver{
+				{
+					Repository: NewRepositorySpec("repo-a", map[string][]string{
+						"ocm.software/test": {"v1.0.0"},
+					}),
+					Prefix:   "",
+					Priority: 2,
+				},
+				{
+					Repository: NewRepositorySpec("repo-b", map[string][]string{
+						"ocm.software/other": {"v1.0.0"},
+					}),
+					Prefix:   "",
+					Priority: 1,
+				},
+			},
+			expectedRepo: "repo-b",
+			assertErr:    assert.NoError,
+		},
+		{
+			name:      "component with prefix match",
+			component: "prefixA/component",
+			version:   "v1.0.0",
+			resolvers: []*resolverruntime.Resolver{
+				{
+					Repository: NewRepositorySpec("repo-a", map[string][]string{
+						"prefixA/component": {"v1.0.0"},
+					}),
+					Prefix:   "prefixA",
+					Priority: 1,
+				},
+				{
+					Repository: NewRepositorySpec("repo-b", map[string][]string{
+						"prefixB/component": {"v1.0.0"},
+					}),
+					Prefix:   "prefixB",
+					Priority: 1,
+				},
+			},
+			expectedRepo: "repo-a",
+			assertErr:    assert.NoError,
+		},
+		{
+			name:      "component not found in any repository",
+			component: "ocm.software/missing",
+			version:   "v1.0.0",
+			resolvers: []*resolverruntime.Resolver{
+				{
+					Repository: NewRepositorySpec("repo-a", map[string][]string{
+						"ocm.software/test": {"v1.0.0"},
+					}),
+					Prefix:   "",
+					Priority: 1,
+				},
+			},
+			expectedRepo: "",
+			assertErr:    assert.Error,
+		},
+		{
+			name:      "version not found in repository",
+			component: "ocm.software/test",
+			version:   "v2.0.0",
+			resolvers: []*resolverruntime.Resolver{
+				{
+					Repository: NewRepositorySpec("repo-a", map[string][]string{
+						"ocm.software/test": {"v1.0.0"},
+					}),
+					Prefix:   "",
+					Priority: 1,
+				},
+			},
+			expectedRepo: "",
+			assertErr:    assert.Error,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			r := require.New(t)
+
+			fb, err := fallback.NewFallbackRepository(ctx, MockProvider{}, nil, tc.resolvers)
+			r.NoError(err)
+
+			repoSpec, err := fb.GetRepositorySpecificationForComponent(ctx, tc.component, tc.version)
+			if !tc.assertErr(t, err) {
+				return
+			}
+
+			if tc.expectedRepo == "" {
+				assert.Nil(t, repoSpec)
+				return
+			}
+
+			require.NotNil(t, repoSpec)
+			spec, ok := repoSpec.(*RepositorySpec)
+			require.True(t, ok, "expected *RepositorySpec, got %T", repoSpec)
+			assert.Equal(t, tc.expectedRepo, spec.Name)
+		})
+	}
+}

bindings/go/repository/component/resolvers/fallback.go

@@ -19,9 +19,15 @@ type fallbackResolver struct {
 var _ ComponentVersionRepositoryResolver = (*fallbackResolver)(nil)
 
 func (f *fallbackResolver) GetComponentVersionRepositoryForSpecification(ctx context.Context, specification runtime.Typed) (repository.ComponentVersionRepository, error) {
+	//nolint:staticcheck // compatibility mode for deprecated resolvers
 	return f.repo.GetComponentVersionRepositoryForSpecification(ctx, specification)
 }
 
 func (f *fallbackResolver) GetComponentVersionRepositoryForComponent(ctx context.Context, _, _ string) (repository.ComponentVersionRepository, error) {
 	return f.repo, nil
 }
+
+func (f *fallbackResolver) GetRepositorySpecificationForComponent(ctx context.Context, component, version string) (runtime.Typed, error) {
+	//nolint:staticcheck // compatibility mode for deprecated resolvers
+	return f.repo.GetRepositorySpecificationForComponent(ctx, component, version)
+}

bindings/go/repository/component/resolvers/interface.go

@@ -18,4 +18,9 @@ type ComponentVersionRepositoryResolver interface {
 	// GetComponentVersionRepositoryForSpecification returns a [repository.ComponentVersionRepository]
 	// based on a given repository specification.
 	GetComponentVersionRepositoryForSpecification(ctx context.Context, specification runtime.Typed) (repository.ComponentVersionRepository, error)
+
+	// GetRepositorySpecificationForComponent returns the repository specification that should be used
+	// to access the given component version. This is useful for operations that need to know
+	// the actual source repository of a component (e.g., transfer operations).
+	GetRepositorySpecificationForComponent(ctx context.Context, component, version string) (runtime.Typed, error)
 }

bindings/go/repository/component/resolvers/pathmatcher.go

@@ -94,3 +94,10 @@ func (p *pathMatcherResolver) GetComponentVersionRepositoryForComponent(ctx cont
 func (p *pathMatcherResolver) GetComponentVersionRepositoryForSpecification(ctx context.Context, specification runtime.Typed) (repository.ComponentVersionRepository, error) {
 	return p.getRepository(ctx, specification)
 }
+
+func (p *pathMatcherResolver) GetRepositorySpecificationForComponent(ctx context.Context, component, version string) (runtime.Typed, error) {
+	return p.specProvider.GetRepositorySpec(ctx, runtime.Identity{
+		descruntime.IdentityAttributeName:    component,
+		descruntime.IdentityAttributeVersion: version,
+	})
+}